The disclosure relates to solar cells and methods for manufacturing the same, and more particularly to solar cells with CIS-based absorber layers. Solar cells are photovoltaic components for direct generation of electrical current from sunlight. Due to the growing demand for clean sources of energy, the manufacture of solar cells has expanded dramatically in recent years. The absorber layer of the solar cell absorbs photons from light and converts the photons of the solar energy directly into electricity and the absorber layer is therefore important in the functionality of a solar cell.
CIS-based absorber layers are popular absorber layers in solar cells. CIS-based absorber layers are pentameric Cu-III-VI2 alloy systems that include copper, a group III element such as indium, In, and gallium, Ga, and a group VI element such as selenium, Se, and sulfur, S. Examples of CIS-based absorbers include selenides such as CuInSe2 and Cu(InGa)Se2, sulfides like CuInS2 and Cu(InGa)S2 and composite CIS-based absorbers such as Cu(InGa)(Se,S)2 compounds.
Some absorber layers, including CIS-based absorber layers, have a gradient of one of their components from the top to the bottom of the film, and the gradient represents a one-dimensional distribution of a component or a ratio from the film top to the film bottom.